A wide variety of flame proofing or fire retarded polymer compositions are known. In the case where the polymer is a polyester such as polyethylene terephthalate (PET) or polybutylene terephthalate (PBT) it was known to flame retard with brominated polystyrene and an antimony compound. It was further known that a dry rather than a wet or hydrated antimony compound was required for addition to PET or PBT. Japanese Patent Application No. 64-83995 (TEIJIN LTD.) discloses a flame retardant composition of brominated polystyrene with an auxiliary antimony compound and a brominated dioctyl phthalate.
Other patents relating to flame proofing and fire retarding compositions and the state of the art include: U.S. Pat. No. 3,723,139; U.S. Pat. No. 3,816,367; U.S. Pat. No. 3,892,667; U.S. Pat. No. 3,897,389; U.S. Pat. No. 3,951,905; U.S. Pat. No. 4,035,333; U.S. Pat. No. 4,338,243; U.S. Pat. No. 4,362,658; U.S. Pat. No. 4,713,407; U.S. Pat. No. 4,729,854; U.S. Pat. No. 4,786,663; U.S. Pat. No. 4,814,130; U.S. Pat. No. 4,983,660; U.S. Pat. No. 5,021,495; U.S. Pat. No. 4,034,439; U.S. Pat. No. 5,115,010; U.S. Pat. No. 5,177,132 and U.S. Pat. No. 5,258,434.
Yet in spite of what was previously known concerning useful means for fire proofing or flame retarding polyester and polymer compositions, a need still existed to provide a means to use lower amounts or employ simplified processes than had previously been used.